Mixing aggregates with asphalt and cooling



y 2 3 c. R. ARNOLD 1,859,324

MIXING AGGREGATES WITH ASPHALT AND COOLING Filed Nov; 28, 1928 l VENTOR air/a0 ATTORNEYS 4 apparatus for Patented May 24, 1932 UNITED STATES PATENT, OFFICE omen. ARNOLD, or ATLANTA, eEone 1 MIXING AGGREGATES WITH ASPHALT AND COOLING Application filed November 28, 1928. Serial No. 822,838.

My invention relates to the method of and producing a combination of asphalt or other bituminous binder with mineral aggregates such as sand or crushed stone adapted for use in road work or for other surfacing such as flooring, roofing, and the like.

v invention is particularly directed toward producing a mixture of mineral aggregates and oils, thoroughly mixed while maintained heated and thereafter cooled in a manner to permit the mixture to be stored cold and used cold at any time without reheating the same. I

More specifically my invention contemplates mixing the heated ingredients, cooling them while agitating the particles of the mixture and separating them to prevent their permanent adherence to one another.

Other objects relate to the specific apparatus referred to below.

These and other objects will appear more fully from the following description when considered in connection with the drawings wherein:

Fig. 1 is a side elevation of one my apparatus may assume and Fig. 2 is a transverse sectional view of the miiiling drums and hoppers associated therewit In carrying out my invention it is essential that the mineral aggregates or sand be thoroughly mixed with the heated bituminous oils and that thereafter the. mixture be cooled while the particles are being agitated "and separated into relatively small portions. Thereform which after the product may be stored without theliability of the portions of the mixture becoming so thoroughly bound together as to prevent their being used Without being. reheated. 7

Referring to the drawings wherein I have illustrated one form of apparatus for carrying out my process, the mineral aggregates preferably first heated and such for example as sand are first placed in a suitable hopper 4 preferably of the self weighing type and provided with means for discharging the mineral aggregates into the mixer. Such means is in icated diagrammatically at 6.

The apparatus includes a mixing drum 8 length of the drum 8 a continuation of the pi pipe 22 forms a continuation of the pipe 18,

I in the outletpipe ingpipe. 24.

rotatable on an axis 9 during the use of the apparatus. The drum 8 is preferably of the form shown in the drawings and includes an enlarged cylindrical central portion 10 and cone shaped end portions 12 and 12' converging toward the axis of rotation of the drum. The central or enlarged portion 10 ofthe drum is formed with a closure 14 movable to or from position to obstruct the central opening 15 of the drum. The inner surface of the drum 8;may be provided with suitable agitating blades 16 preferably placed upon the portion 10 as well-as on-the cone shaped portion 12 and 12' so as to thoroughly mix the material within the drum and to have a constant tendency to throw the material toward the outer portion 10 and openin 15 of the drum for the purposes referred to low.

The outer ends of the cone shaped portions 12, 12' terminate in hollow pipes 18, 18 rotatably supported as indicated at 19, 19. The rod 18 includes an inner discharge portion 17 extending substantially through the and apertured to permit the discharge of bituminous oils into the interior of the drum. An inlet pipe 20 formed with the closure valve 21 constitutes pe. 18. The outlet the pipe 22 likewise bein provided with a closure valve 23. ,The out et and inlet pipes 22 and 20 are provided respectively for pro duoing a partial vacuum. within the drum 8 useful for drawing the bituminous oils into the, drum and'for improving the resultant pavement material mixture. v

A partial vacuum may thus be produced 22 and drum 8 by any suitable suction means attached to the conduct- The inlet pipe 20 terminates within a vessel'26 provided for the purpose of heating the asphaltic. oils as by means of the furnace 28, diagrammatically illustrated.

The entire central portion 10 of the drum 8 is surrounded by a hopper 30 for med with a receiving openin 32 so that the material maybe discharged rom the drum 8 by merely displacing the door Hand thereafter rotating the drum. The hopper 30 includes a discharging spout 34 positioned to discharge valve as it is permissiblelto close the opening 15 and into the cooling drum 36 referred to below.

The cooling drum 36 is -.constructed substantially the same as the drum 8 except that the pipe 17 which introduces the bituminous oils into the interior thereof-is omitted. The drum 36 is formed with a. similar opening 15 normally closed by the closure 14' and rotates in the same manner as the drum 8. The outlet pipe 38 for the drum 361is provided with a valve 39 and connects with the vacuum producing mechanism by means of the pipe 24. The inlet pipe 40 is notrequired to have a allow a predetermined flow of air into and through the drum 36 at all times th drum is in use.

A hopper 42 surrounds the central portion of the drum 36 and is substantiall the same asthe hopper 30 so that further escription thereof appears unnecessary.

' The materials discharged per 42 fall upon the screens 44 and 46'where the same is separated into relatively small portions, the separated materials falling upon a conveyor belt 48whi'ch transports the material toa suitable place of discharge.

The operation of the above apparatus is as follows: e

The mineral aggregates, such as sand, are first placed within the hopper 4 and the r0tation of the drum 8 is stopped with the opening 15 of the drum'8 directly beneath the dis charge outletof the hopper:4. The mineral aggregates are then introduced into the drum 8. The'clos'ure 14 is then movedto tightl the drum is rotate toiprovide a partial The valve 23 is opened andthe valve 21 vacuum within the drum 8 is opened to permit the desired amount of to be drawn into the hopper,

bituminous oils after which the valve 21-is closed and the hopper 8 further rotated untilthe mineral aggregates and oils are thoroughly mixed while subjected to the partial vacuum produced at 24 and without the dissipation of any substantial portion of the initial heat. After the ingredients are thoroughly mixed the valve 23 is closed and the cover 14 removed, the

been previously stopped in drum 36 having the pgsition shown in Fig.2 with the opening 15 neath the discharge opening 34 of the hopper 30.

otation of thedrum 8 thereafter causes the discharge of all of thematerial within the drum, the construction of which assures the passage of the mixture to the central portion of the drum for-discharge the hopper 30 and drum "36.

A new supply of oils is thereafter added to the drum 8 and the process repeated. The material introduced into the drum 36 is then cooled and agi-. tated by rotation of the drum 36" while main- After the material in the drum 36 is cooled to from into

mineral aggregates and subjecting the same to substantially normal or atmospheric temperature the cover of this drum 1s removed an the material discharged into and through the hopper 42 where it passes through the screens 44 and 46 and onto the conveyor 48 from which it is discharged at a suitable point.

p The above apparatus is found to produce a uniform product in-which the separate portions of the mixture are not so firmly bound .together even after storage as to prevent mixture under the influence of the air flow Y through the pipes 38'and 40. from the hop- The shape of the drums 8 and 36 facilitates the discharge of material from the drums and tends to prevent the material from passing into the' inlet or outlet pipes since the material'is automatically moved toward the outer cvlindrical portion 10.0f the drum."

f It will be understood that plenum or pressure greater vacuum may be applied to produce the cooling draft through the cooling drum.

Having now described my invention what I desire to secure as Letters Patent is;

1. The method'of preparing a composition of matter for application in a cold state comprising mixing mineral ag regates and bituminous oils while maintained heated, agitating said mixture while artificially cooling than normal instead of partial thesame and then separating the cooled products into relatively small portions.

2. The method of preparing a composition of matter for application in a cold state comprising mixing mineral aggregates and bituminous oils while maintained heated, agitating "said mixture in a closed space while subjecting the same to an air flow through said space resulting in artificially cooling the same and subsequently separating the cooled products into relatively small portions.

3. The method of preparing a composition of matter for application in a cold statecomprising mixing mineral aggregates and bi-- tuminous oils while maintained heated, agitating said mixture while subjecting the same to a partial vacuum and artificially'cooling the same and separating the cooled products into relatively small portions. 7 I

4. The method of preparing a composition of matter for application in a cold state comprising mixing min'eral'aggregates and bituminous oils while maintained heated, agitating said mixture in a confinedspace while an air fiow through said space resulting in artificially cooling the same. 5. An apparatus for producing a compositlon of matter comprising a rotatable mixing 1 drum, means for introducing mineral aggregates and bituminous oils into the same, means for producing a partial vacuum in said drum during agitation of the contents 5 by rotation'of the drum, a rotatable cooling drum, means for passing the cooling agent through the drum during rotation and means for passing the mixture from the mixing drum to the'cooling drum'.

n I 6. An apparatus for producing a composition of matter comprising a rotatable mixing drum, means forintroducing mineral aggregates and bituminous oils into thesame, a rotatable cooling drum, means for passing 1; the mixture from the mixing drum to the cooling drum and means for producing an air flow through said cooling drum.

' 7. An apparatus for producing a composition of matter comprising a rotatable mixing 2o drum, means for introducing mineral aggregates and bituminous tatable cooling drum, means for passlng the mixture from the mixing drum to the cooling drum and means for, producing a partial vacuum in said coolingdrum.

8. An apparatus for producing a composition of matter comprising a rotatable mixing drum, means for introducing mineral aggregates and bituminous oils into the same, a rutatable cooling drum, means for passing the mixture from the mixing drum to the cooling drum and means for producing a partial vacuum in said drums.

An apparatus for producing a composition of matter comprising a rotatable mixing drum, means for introducing mineral aggregates and bituminous oils. into the same, a rotatable cooling drum, means for passing the mixture from the mixing drum to the cooling drum, means for producing a partial vacuum in said drums, said means connecting with said drums coaxially of the latter.

10. An apparatus for sition of matter comprising a rotatable mixing drum, means for introducing mineral aggregates and bituminous oils into the same, a rotatable cooling-drum, said drums being formed with circumferentiall enlarged central portions andcone shaped ends converging toward the axes thereof, means for passing the mixture from the mixing drum to the cooling drum, means for producing a partial vacuum in said drums, said means connecting with said drums coaxially of the latter adjacent the most restricted portions of said drums.

11. In a device of the character described, a rotatable mixing drum, said drum includin a radially enlarged central portion pro- ,vi ed with a central opening and closure therefor and converging end portions formed with openings constituting inlet and outlet means respectively,

drum through said central opening, surrounding the central portion of 8 pper the drum oils into the same, a roproducing a compo container and means for charging the" and a cooling drum having an enlarged central portion and converging end portions arranged beneath said mixing drum and ohavv ing a central opening and closure therefore in its enlarged portion in line with the discharging spout of said hopper.

12. In a device of the character described, a rotatable mixing drum, said drum including a radially enlarged central portion and converging end portions formed with openings constltuting inlet and outlet means respectively, means for inducing circulation of the coolin agent in said drum through said inlet and outlet means while the drum is rotating and removable means formed on the central portion of said drum for providing access to the interior thereof and for permitting the: discharge of the contents thereof and means for charging the drum through said central portion.

13. A method of-preparing a composition of matter suitable for application in a cold state consisting in mixing a mineral aggregate and bituminous material in heated condition by agitatin the mixture in a suitable container while subjected to a partial vacuum then delivering the mixture into another container wherein it is subjected to the action of a cooling agent circulating through it during agitation.

14. A method of preparing a compodtion of matter comprising a mineral ag gate and bituminous material consisting in agitatingsaid aggregate and material while in heated condition in a suitable container and while subject to the influence of a vacuum then delivering the mixture into another container and agitating the mixture therein while said container is in sealed condition and during flow of air circulating through said container as a cooling agent for the mixture.

, 15. A method of preparing a composition of matter comprising a mineral aggregate and bituminous material consisting in mixing the aggregate and material in a suitable sealed container while in heated condition I by rotation of said container and while subect to the influence of a vacuum therein then mixture into another rotatable delivering the cooling the same by agitation of the mixture in said container while sealed therein and while subjected to the cooling influence of a cooling agentcirculated therethrough by producing a partial vacuum therein. j

Signed at Atlanta in the county of Fulton and tate of Georgia, this 20th day of November A. D. 1928.

- CRAIG R. ARNOLD. 

